Diesel Lift Pump

[a64pilot]

My boat has an electric fuel pump installed inline by the manufacturer. It's sole purpose is to make bleeding easy for filter changes, neat idea, but the pump is bad, doesn't work and it's an SU pump, God knows where I can find a replacement.
Bleeding with the wobble lever on the mechanical pump on the Yanmar isn't that bad, but I can see how having a higher volume pump would be nice.

Why not just use an outboard squeeze bulb instead of an electric pump, will one not work? Lots cheaper and what's to break?

[Dulcesuenos]

If the tank will gravity feed you should be fine as I've done this on 2 diff westerbekes. If it needs to pull fuel and fuel doesn't readily flow from the tank you may need the electric pump to avoid strain on the system. Napa sells a Facet diesel pump for $63. And it was identical to the OE pump.

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[dandkg]

we added 1 to our setup for that reason we found ours at any auto parts store as above sailor says just ask counter person for electric diesel pump. may have to check couple stores some just carry gas electric pumps have a great 1

[Canibul]

Do you wire that to the starter/ignition switch so the pump turns on with the key? does it run the entire time you have the diesel running?

[a64pilot]

On mine, it's wired to the ignition so that the pump won't run unless the ignition is on, but the pump is left off only used for bleeding. I suppose its a back up for the lift pump, should the lift pump fail you should be able to continue to run by turning on the electric pump, only problem with that is 99% of lift pumps failure mode is for the diaphragm to rupture and allow Diesel into the engine oil. Smarter I think to just have a spare mechanical lift pump.

I was trying to not have to buy another electric pump, I have an aircraft pump that I could install, but liked the idea of a simple squeeze bulb better, just wondered if anyone was doing it, or if they had tried and it didn't work for some reason.
Squeeze bulb you could slow down and pump slowly as the filter filled completely, electric pump is on or off.

My tank is well below the engine, fuel has to be pumped

[bornyesterday]

There are plenty of small electric fuel pumps, including SU's, on evilbay.

Most are much cheaper than SU's but I suspect won't be as quiet. I'll probably get an SU for my diesel heater unless anyone can recommend a quiet pump that's cheaper.

[gjordan]

I had trouble with lift pumps on my Perkins. First, it leaked and caused a runaway, so I replaced it, then a few weeks later I heard a loud snap in the engine room, and the engine died. I was frustrated at that point, and bypassed the lift pump with a Napa 12 volt pump, wired into the ignition switch. I ran it like that for 3 or 4 years until I sold the boat. My next Perkins had a lift pump go bad (in my backhoe) and I went straight to Napa Auto, bought a 12 volt pump and wired it in. The interesting thing about that episode was that the wire came loose from the back of the switch, and the tractor kept working just fine. Since the fuel tank is above the engine, it has enough gravity pressure to run without any lift pump. It must not take very much pressure to feed the injection pump since the tank is less than 6 inched above the top of the engine. A 12 volt fuel pump, and some spare wire was always in my tool kit for doing deliveries. ______Grant.

[cal40john]

Originally Posted by a64pilot

On mine, it's wired to the ignition so that the pump won't run unless the ignition is on, but the pump is left off only used for bleeding. I suppose its a back up for the lift pump, should the lift pump fail you should be able to continue to run by turning on the electric pump, only problem with that is 99% of lift pumps failure mode is for the diaphragm to rupture and allow Diesel into the engine oil. Smarter I think to just have a spare mechanical lift pump.

I was trying to not have to buy another electric pump, I have an aircraft pump that I could install, but liked the idea of a simple squeeze bulb better, just wondered if anyone was doing it, or if they had tried and it didn't work for some reason.
Squeeze bulb you could slow down and pump slowly as the filter filled completely, electric pump is on or off.

My tank is well below the engine, fuel has to be pumped

The operators manual for the Yanmar 3GM series engine states that if the fuel tank is greater than 0.8 meters below the fuel feed pump on the engine an electric pump should be added.

The PO put one on my boat as the tank is low in the keel. While troubleshooting a fuel problem I found the engine would run on either the diaphragm pump or the electric alone, so I assume they are addressing a longevity issue with the diaphragm pump.

[jannw]

To answer your question, it seems like an excellent idea, and one I have read about before, to use a inline fuel bulb to prime a diesel motor. If you had asked the question in a few months I could answer directly as it is a change I also intend to make to my yacht, but right now I can only confirm that I have read of someone else making the same alteration with good results, but I can't remember where I read it.

[ontherocks83]

Dumb question but can a gas hose be used with diesel? I don't know if there is a difference in hose materials for diesel and gas but I would be wondering if the diesel would "eat" through the gas hose, just like if you use the wrong rubber seals with brake fluid the fluid can eat through the seals. Or is fuel hose the same all the way around. Just a thought / precaution. Any one have experience or advice on this?

[cal40john]

Originally Posted by ontherocks83

Dumb question but can a gas hose be used with diesel? I don't know if there is a difference in hose materials for diesel and gas but I would be wondering if the diesel would "eat" through the gas hose, just like if you use the wrong rubber seals with brake fluid the fluid can eat through the seals. Or is fuel hose the same all the way around. Just a thought / precaution. Any one have experience or advice on this?

I think someone has posted on CF in the past that the bulb hardened after a time.

[model 10]

Originally Posted by ontherocks83

Dumb question but can a gas hose be used with diesel? I don't know if there is a difference in hose materials for diesel and gas but I would be wondering if the diesel would "eat" through the gas hose, just like if you use the wrong rubber seals with brake fluid the fluid can eat through the seals. Or is fuel hose the same all the way around. Just a thought / precaution. Any one have experience or advice on this?

I bought a bit of the latest and greatest approved ethanol gas hose , and it had a Teflon lining. So that means it would handle just about anything.

[TacomaSailor]

OP said: "Why not just use an outboard squeeze bulb instead of an electric pump, will one not work? Lots cheaper and what's to break?"

I did exactly that in 1998 on our Yanmar 4JH-2E. It has worked perfectly for the last 16 years and a lot of cruising miles. The bulb split in 2004 and it took a couple minutes to replace it.

The outlet tube from our diesel tanks are 22" below the inlet to the Racor filters and the squeeze bulb easily moves the fuel from the tank up to the Racor.

Just make sure you get a bulb that is OK with diesel.

[Cheechako]

The squeeze bulb works well, I have used one before. But for some reason mine got soft over time with diesel. The rubber seemed to swell and get spongy. maybe it was the diesel additive? There are small electric pumps available at NAPA auto parts etc. They are cheap and easy to find.

[a64pilot]

Originally Posted by ontherocks83

Dumb question but can a gas hose be used with diesel? I don't know if there is a difference in hose materials for diesel and gas but I would be wondering if the diesel would "eat" through the gas hose, just like if you use the wrong rubber seals with brake fluid the fluid can eat through the seals. Or is fuel hose the same all the way around. Just a thought / precaution. Any one have experience or advice on this?

I don't know, I've never heard of either gas or Diesel hose, just fuel hose?
I put quite a bit of automotive fuel hose on my Backhoe about 30 yrs ago, it's still fine.
But with ULSD, BioDiesel and ethanol gas, who knows?